[Lowfer] PowerLineComm & AR

[James Moritz]

At 17:53 15/05/2003 -0400, you wrote:
>I recall something about a similar power grid system used for public
>comms.
>by the Brits, think it was tv, but not sure if on-going.
Dear Lowfers,

The RSGB in the UK, and other European Amateur radio societies also, have 
been campaigning on this issue for several years. In the UK it is known as 
Power Line Telecommunications - there have been several localised trials as 
a medium for internet access, but it is currently not "legal", mainly 
because to be feasible, the amount of RF power injected into the power 
lines has to be high in order to overcome high noise levels and losses. 
This in turn leads to radiated noise levels far in excess of what is 
permissible under current EMC regulations. Therefore the various PLT 
consortiums are lobbying to have the EMC limits relaxed so they can sell 
their system, while all the RF spectrum users' groups are campaigning to 
stop this happening.

So far, the PLT consortiums have not been very successful - one lot called 
Nor.Web went bust after failing to get their system off the ground - but 
they are still keeping up the pressure, especially since the government 
keeps promising "Broadband Britain" to everyone. It seems to me if they put 
the same amount of effort into laying proper data cables down some streets, 
the results would be better for everyone, but there you go.

There are some articles on PLT on the RSGB web site 
http://www.rsgb.org/emc/pltnew.htm . The current concern is mostly with HF; 
I don't know if any of the proposed systems would operate in the LF range - 
not much bandwidth there, and as we already know, even higher noise levels. 
But if nothing else it would probably mean another load of switch-mode PSUs 
drifting up and down!

Cheers, Jim Moritz
73 de M0BMU